Spring drive



Dec. 3, 1935- e. E. LE COUNT SPRING DRIVE Filed June 1, i934 r ge. E. LeCount. W efi li l-lls Attorne Invent ow:

Geo 1 1+ atenicd Dec. 3, 1335 UNITED STATES PATENT OFFICE srnnvc. nmva New York Application June 1, 1

1 Claim.

My invention relates to spring drives. In the operation of valves, switches and some other devices, it is sometimes desired that an intermittently driven device be operated very quickly by some driving device which operates and moves much more slowly. The general object of the present invention is to provide an improved construction and arrangement of spring drive of this general type of which an example is disclosed in my United States Letters Patent No. 1,891,101, issuodpecember 13, 1932.

Other objects and advantages will be explained in the following description taken in connection with the accompanying drawing in which Fig. 1 is a, longitudinal sectional view of a preferred form of spring drive constructed in accordance with the invention; Fig. 2 is a diagrammatic perspective view of the spring drive, parts being broken away to reveal details and the drive being shown as applied in the operation of an electric switch; and Figs. 3 and 4 are perspective views of a simplified form of the invention.

Like reference characters indicate similar parts in the different figures of the drawing.

The simplified form of the invention shown in Figs. 3 and 4, which will be first described, in-.- cludes two shafts III and II aligned along a common axis, the shaft I being a driving shaft which may be rotated in either direction by any suitable source of power and the shaft I I being a driven shaft which may be connected to any load which the spring drive is adapted to operate. Disks l2 and I3 are secured to the shafts I0 and II respectively. The disk IS on the driven shaft II has a projection or tooth I I on its outer edge and two spring latches or stops I5 and it are spaced about the periphery of this disk and normally held in the path of the tooth II. The end of each of the stops I5 and I6 is beveled so that it will yield and permit rotation of the driven shaft II in one direction but will prevent its rotation in the other direction. The stop I5 is beveled to prevent rotation of the driven shaft II only in one direction and the stop It is oppositely beveled to prevent rotation of the driven shaft only in the other direction. A cam H on the disk. I2 isarranged to strike pins I8 and I9 on the stops I5 and I6 respectively and lift each stop out of the path of the tooth I4 as the cam passes the stop. A helical spring 20 surrounding theshaft II has its two ends 2| and 22 projecting radially at opposite sides of two pins 23 and 24 fixed respectively to the two disks I2 and It. The spring 20 is preferably normally under some tension so that it tends to hold the two 934, Serial No. 728,488

pins 22 and 24 in the same radial position as shown in Fig. 3.

The spring drive which has been described -is operated by rotating the driving shaft II.

Assume that the shaft I0 is rotated in the direc- 5 tion of the arrow 25 with the parts starting from the positions indicated in Fig. 3. This will rotate the disk I2 with its cam I1 and pin 23 which will act through the spring 20, the pin 24 and the disk I3 to rotate the driven shaft in the same 10 direction so long as the driven shaft is free to rotate. When the tooth it reaches the stop II as shown in Fig. 4, further rotation of the driven shaft I I is prevented. The pin 24 is also stopped and holds the end 22 of the spring 20 while the pin 23 continues to move the other end 2| of the spring and increase its tension. Finally, the cam ll reaches the pin I8, as shown in Fig. 4, and pushes back the stop I5 to release the tooth I4 so that the driven shaft II is free to rotate. As 80 soon as the tooth I4 is released, the driven shaft I I is rotated rapidly by the spring until the two pins 23 and 24 are again together as shown in Fig. 3. Just as the pin 2| reaches the other pin 22, the end 22 of the spring 20 is stopped 25 by the pin 23. The pin 24 with its disk I3 and the driven shaft II is stopped at the same time, by the end 2| of the spring. The driven shaft II and the parts which rotate with it may have considerable inertia but they are stopped without serious shock because of the resiliency of the spring 20. If the driving shaft III continues to rotate in the direction of the arrow 25. the action which has been described will be repeated.

The spring drive which-has been described may be operated in either direction. If the driving shaft I0 is rotated in a direction against the arrow 25, the driven shaft II will rotate with the driving shaft until the tooth I4 and the driven shaft are stopped by the latch I6. The spring 20 is then tensloned by the pin 23 until the cam I'I pushes back the latch I6 and releases the tooth I4. The driven shaft II is then free and is rotated rapidly through part of a revolution by the spring 20, the driven shaft being stopped without serious shock by the resilient end 22' of the spring.

The preferred form of the invention is shown in Fig. 1 and the explanatory view in Fig. 2 shows the same form but with the parts separated to indicate the construction more clearly. 'L'nis preferred form of the invention includes a driving shaft III and a driven shaft II. A disk l2 rotatable on the driven shaft II and a disk I2 rigidly mounted on the driving shaft in are rlgidly connected by a cylinder I2 to form a casing. The driving shaft I8 and the driven shaft II are relatively rotatable about a common axis. A disk 26 is fixed to the driven shaft I I between two disks 21 and 28 which are rotatable on the driven shaft. A pin 29 on the disk 26 extends into a groove 38 in the disk 21 and a pin 3| on the disk 26 extends into a groove 32 in the disk 28, the grooves 38 and 32 being concentric with the common axis of the disks. A helical spring 28 is connected between the two disks 21 and 28 and constantly tends to rotate these two disks in opposite direction relatively to each other so that each of these disks is normally held with one end of its groove pressed against its respective pin but with the grooves extending around the driven shaft II in opposite direction from their pins. A pin 33 on the disk 21 extends into one end of a groove 34 in the disk I2 and a pin 35 on the disk 28 extends into one end of a groove 36 in the disk I 2, the grooves 34 and 36 extending concentrically about the common axis of the disks and in opposite directions from their respective pins.

A disk I3 having a tooth or projection I4 is mounted rigidly on the driven shaft II and two one-way spring-pressed latches or stops I5 and I6 are arranged in the path of the tooth I4. The stop I5 has a pin I8 which may be engaged by a cam I1 on the cylinder I2. The stop I6 has a similar pin I9 which may also be engaged by the cam I1.

As an example of one possible use of the ap plication of the spring drive which has been described, the driven shaft II' is shown in Fig. 2 connected to a Geneva gear including a driving member 31 and a gear wheel 38, the gear wheel 38 being connected by a shaft 39 to a switch contact 48 which is movable over a plurality of fixed contacts H. The driving shaft I8 may be rotated in any desired manner as by the gear wheels 42 and 43.

The driven shaft I I may be rotated in either direction desired by rotating the driving shaft I8 in the corresponding direction. Suppose the driving shaft I8 to be rotated in the direction of the arrow 25. As the driving shaft starts to rotate, the driven shaft II will rotate with it until the tooth I4 reaches the stop IS, the driving shaft being yieldingly connected to the driven shaft by the disk I2, cylinder I2", disk I2, pin 35, disk 28. spring 28, disk 21, pin 29 and disk 26. When the tooth I4 reaches the stop I6, the driven shaft II with its disk 26 and pin 29 can no longer rotate. The pin 29 thus holds the disk 21 and its end of the spring 28 from further rotation. The disk I2 then acts through the pin 35 and the disk 28 to increase the tension of the spring until the cam I I reaches the pin I9 and pushes back the stop I6 to release the tooth I4. The tension of the spring on the disk 21 then acts through the pin 29 and the disk 26 to rotate the driven shaft rapidly through part of a revolution and consequently to rotate the movable switch contact 48 to the next fixed contact 4I. While the 5 spring was being tensioned, the disk 28 was rotated to carry its groove 32 to the other side of the pin 3| from that shown in Fig. 2. After the spring was tensioned and the tooth I4 was released by the cam I1, the rapid rotation of the m driven shaft carried the pin 3| along its groove 32 until it and the driven shaft were stopped by the opposite end of the groove. The driven shaft is stopped, however, without any serious shock because of the resiliency of the spring 28 con- 1:, nected to the disk 28.

If the driving shaft I8 is rotated in the direction against the arrow 25, then the driven shaft II will rotate with it until the tooth I4 reaches the stop I5. The disk I2 on the driving shaft I8 20 then acts through the pin 33 and the disk 21 to tension the spring, the opposite end of the spring being held from rotation by the disk 28, the pin 3| and the disk 26 on the driven shaft. When. the cam I1 reaches the pin I8, the stop I5 is pushed back and the tooth l4 with the driven shaft released. The spring 28 then acts through the disk 28, pin 3| and the disk 26 to rotate the driven shaft I I rapidly until the pin 29 is stopped by the end of the groove 38 in the disk 21, the 30 driven shaft being stopped without any serious shock because of the resiliency of the spring 28. The driven shaft II may thus be rotated rapidly through part of a revolution any number of times and in either direction desired by ro- 35 tating the driving shaft I8 in the desired direction.

The invention has been explained by describing and illustrating difierent forms and a possible application thereof but it will be apparent that changes may be made without departing from the spirit of the invention and the scope of the appended claim.

What I claim as new and desire to secure by Letters Patent of the United States, is, A spring drive including axially alined driving and driven shafts, a helical spring surrounding the common axis of said shafts, means controlled by the driving shaft for tensioning the spring from either end, means controlled by the driven 50 shaft for holding either end of the spring while it is being tensioned from the other end, there being a lost motion connection between said holding means and each end of the spring, and means for automatically releasing the driven shaft after the spring has been tensioned, said driven shaft being free to rotate when released until stopped by one of saidlost motion connections.

GEORGE E. LE COUNT. 

